Salt: How Bad?

Here at Diabetes Flashpoints, we’ve often discussed the need for people with diabetes to limit their intake of salt. After all, the Centers for Disease Control and Prevention (CDC) recommend that anyone with an elevated cardiovascular risk — including all people with diabetes — consume no more than 1,500 milligrams of sodium daily. The American Diabetes Association (ADA) endorses a slightly higher, but still low, limit of 2,300 milligrams. By contrast, the average American consumes about 3,400 milligrams each day.

But recently, some researchers have introduced evidence that casts doubt on these recommendations. As we noted in a post last month, there is ample evidence to suggest that sugar raises blood pressure, and the risk of cardiovascular disease, much more than salt. There has also been evidence in some studies that the lowest risk of death from cardiovascular disease is found among people whose sodium intake is close to the American average of 3,000–4,000 milligrams. Now, a new study involving seniors is leading researchers to question just how important sodium intake is in the first place.

Advertisement

Published last week by the journal JAMA Internal Medicine, the study followed a racially diverse group of seniors, ages 71–80 when the study began, for 10 years. Each participant answered a food frequency questionnaire, from which researchers calculated their average daily sodium intake. Ten years later, 881 participants had died, 572 had developed cardiovascular disease (meaning they didn’t have it initially), and 398 had developed heart failure. There was no statistically significant difference between sodium intake and any of these outcomes. When participants were grouped according to a daily sodium intake below 1,500 milligrams, between 1,550 and 2,300 milligrams, and above 2,300 milligrams, the death rate after 10 years was found to be lowest in the middle group (30.7%), but it wasn’t much different in the low-sodium (33.8%) or high-sodium (35.2%) groups, and these differences were not statistically significant (meaning they could have been due to pure chance). Even when the researchers compared sodium intake with the number of calories participants consumed and their body-mass index (a measure of body weight that takes height into account), sodium intake had no significant effect on any outcomes.

In an article on the study at MedPage Today, doctors were skeptical of the importance of the study’s findings. Some acknowledged that many seniors may not be sensitive to sodium intake, but noted that this study looked only at seniors who were living in their community, rather than in an extended-care setting. This means it may have excluded those who are most sensitive to sodium in their diet. Still others noted that food questionnaires can be unreliable, so it’s possible that some of the participants who died actually had a far greater sodium intake than they reported. And finally, the study’s grouping of participants based on sodium intake may have been too narrow in its ranges; some doctors believe that the greatest benefit from sodium reduction is seen when someone consuming 8,000 to 10,000 milligrams daily reduces his or her intake to below 4,000 milligrams.

What’s your take on salt — do you try to limit your sodium intake to the ADA-recommended 2,300 milligrams, or less? If so, have you found this limitation to be difficult or unpleasant? Do you avoid certain processed foods because of their high sodium content? If you don’t limit your sodium intake according to standard recommendations, why not? Do you trust that groups like the ADA and CDC will change their recommendations if the evidence shifts away from them? Leave a comment below!